Code for 3D printed, bluetooth game show buzzers for playing The Voice at home, powered by Adafruit Circuit Playground Bluefruit boards and a laptop. Find the full story including build instructions in my blog post or check out a quick video of it action on YouTube.
A PC communicates with all of the buzzers over bluetooth, keeps track what order they buzz in, and plays the BOOM sound effect. Each buzzer has an Adafruit Circuit Playground Bluefruit inside, which tells the PC whenever the button is pressed and updates its lights based on the rank information it receives in response. This repo contains code for both sides. Here's a birdseye view of the situation:
- Power on all of the buzzers
- Run
button_central.py(on the PC) - Wait for the buzzers to connect to the PC (buzzer lights will change to blue)
- When someone buzzes in, the PC will play the BOOM and the buzzer will start flashing white - fastest for 1st place, slowest for last
- Buzzing in more than once will play the BOOM, but won't change the player's rank
- Holding any buzzer for longer than 5 seconds will reset the game (clear the rankings and set all buzzers to solid blue - assuming all devices are connected)
- Hitting Ctrl-C will (hopefully gracefully) end the script and disconnect the buzzers
| Color | Bluetooth | Player buzzed in? |
|---|---|---|
| solid purple | disconnected | no |
| solid blue | connected | no |
| pulsing amber | disconnected | yes |
| pulsing white | connected | yes |
See this for other flash patterns used by CircuitPython (you shouldn't see these if everything is loaded and ok).
desktop python scripts that run on the PC
circuitpy CircuitPython that runs on the Bluefruit
docs documentation artifacts
- Follow these steps to install CircuitPython on each Bluefruit board.
After that's done, the device should show up as a Mass Storage Device called
CIRCUITPYwhen you plug it into your PC. - Copy the contents of the
circuitpy/libfolder in this repo to theCIRCUITPY/libfolder on the bluefruit. - Copy
ble_comms.pyandcode.pyfrom thecircuitpyfolder in this repo to the bluefruit's root. - Open a Serial Console and note the BLE MAC address in this message:
Waiting to connect <Address c2:bd:72:af:f5:2c> - Disconnect the USB and supply power using a battery. The LEDs on the Bluefruit should be solid amber or blue, depending if there's a bluetooth connection.
The python script uses bleak to manage the bluetooth connections. I believe it's the only package you'll need to install, but haven't verified this with a fresh install. If you try it, let me know what you find out!
There is an export of the Anaconda virtual environment I was using. It probably includes a lot of extra stuff that you don't actually needed for this to run. But if you want, you can import with conda like this:
conda env create -n ENVNAME --file adafruit.yml
Before the buzzers can connect, the hardcoded MAC addresses for the Bluefruit boards must set.
Update these lines in desktop/button_central.py with the MAC address of your bluefruit devices (see earlier section for how to get MAC address):
one = "C2:BD:72:AF:F5:2C"
two = "E3:55:A0:1B:BB:0B"
three = "d7:10:63:77:a5:d0"
four = "c2:df:0c:e4:c0:6c"
That BOOOOM as all bass. For best results, hook the PC up to a system with at least 20" subwoofers and crank it to 11.
- It seems some bluetooth adapters can't run all four simultaneous connections smoothly. Try connecting just one buzzer at a time (comment out the rest in
button_central.py) and disconnect other unrelated bluetooth devices. - Killing the PC app with Ctrl-C usually works, but sometimes the bluetooth can get in a weird state. Try rebooting the terminal, the PC, the Bluefruit boards, etc...
- See general CircuitPython troubleshooting
- Let's just say this project was hacked together for scream-a-long karaoke at a yearly weekend cabin trip. Use at your own risk.